The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Hardfacing relates generally to techniques or methods of applying a hard, wear resistant alloy to the surface of a substrate, such as a softer metal, to reduce wear caused by abrasion, abrasion, corrosion, and heat, among other operational or environmental conditions. In some applications, there exists abrasion in a corrosive environment, which can cause excessive and accelerated wear of the base metal.
A variety of methods are available to apply the wear resistant alloy to the substrate, among which includes welding, where a welding wire is deposited over the substrate surface to produce a weld deposit that is highly wear resistant. The welding wire may include a solid wire, metal-cored wire or a flux-cored wire, wherein the metal-cored wire generally comprises a metal sheath filled with a powdered metal alloy and the flux-cored wire generally comprises a mixture of powdered metal and fluxing ingredients. Accordingly, flux-cored and metal-cored wires offer additional versatility due to the wide variety of alloys that can be included within the powdered metal core in addition to the alloy content provided by the sheath. Cladding uses a similar welding process and generally applies a relatively thick layer of filler metal to a carbon or low-alloy steel base metal to provide a corrosion-resistant surface.
Conventional chromium carbides and complex carbides have exceptional wear resistance, which is attributed to the high concentration of primary chromium carbides in an iron matrix. However, formation of such carbides depletes the matrix of chromium, thus reducing the ability to resist corrosion. Other alloys with increased chromium levels in the matrix are devoid of primary chromium carbides, thus reducing abrasion resistance.
Improved compositions in the areas of hardfacing and cladding are continually desired in the field of welding, especially in environments that are both abrasive and corrosive.